Evaluation of Latent and Active Tuberculosis Development in Patients Receiving Biologic Agent Therapy: A Retrospective Analysis

ObjectiveTo determine the incidence of active TB in patients re-ceiving biological/tsDMARD therapy and to examinethe effects of LTBI prophylaxis and the level of immu-nosuppression on risk.Material and MethodPatients aged ≥18 years who started biological treat-ment between 2019 and 2024 were reviewed retro-spectively. Inclusion criteria: ≥3 months of biological/tsDMARD use, at least one LTBI test (PPD or IGRA)performed before the treatment, and ≥6 months of fol-low-up records. Exclusions: previous active TB, miss-ing baseline data, or follow-up at an external center.Demographics, diagnosis, agent type/duration, addi-tional immunosuppression, BCG scar, LTBI screeningresults, prophylaxis regimen, and adverse events wererecorded. The primary endpoint was defined as activeTB. The relationship between LTBI treatment, levelof immunosuppression, LTBI positivity, and active TBwas examined using Bayesian logistic regression.ResultsA total of 101 patients were reviewed. PPD was per-formed in 69.1% and IGRA in 51.5% of patients; BCGscar was observed in 93.8%. Two cases of active TB(2.0%) were observed: one developed under barici-tinib and the other under bevacizumab. The LTBI pro-phylaxis completion rate was 71.2%, and hepatotox-icity was 11.9%. Bayesian analysis revealed a highbut uncertain risk association with LTBI treatment (OR57.65; 95% CrI 0.93-3303.16), which was consistentwith indication confounding. The likelihood of higherrisk was 78% in the low-moderate immunosuppres-sion group. No independent effect of LTBI positivitywas observed.ConclusionActive TB under biological/tsDMARD therapy is rarebut important. The high risk seen in those receivingLTBI prophylaxis may be a result of clinicians select-ing high-risk patients rather than the treatment itself.The findings achieved in this study suggest that cau-tion is necessary with JAK inhibitors and anti-angio-genic agents and should be confirmed by larger pro-spective studies.